Internal combustion engines utilize oil for various functions, including lubrication, cooling, etc. The oil can be circulated through various engine passages from a common reservoir, such as an oil pan. Degradation of the engine oil may occur for a variety of reasons such as due to water build-up in the oil and so on. For example, water formed as a byproduct of combustion can condense and migrate into the engine oil. Additionally, engines combusting hydrogen fuel, for example, can produce significantly more water than engines combusting gasoline.
Excessive water build-up can degrade the oil and thus lead to increased engine component wear. In turn, increased component wear may increase degradation rates of various engine components, such as bearings, piston rings, intake valves, camshafts, etc. Increased water in the oil may also lead to oil starvation caused by ice forming over an oil pickup tube. As another example, oil starvation may be caused by the oil-water mixture viscosity becoming too low to support oil pump operation.
One method to address oil degradation in a gasoline engine is discussed in U.S. Pat. No. 6,535,001. A sensor coupled to an oil pan determines when oil degradation occurs. A method is described, which among other things, determines if the oil in the oil pan has become contaminated with water and/or anti-freeze. If it is determined that the oil has become contaminated, the driver is alerted of “high water content” via a warning light located on the dashboard. After the warning light is illuminated, the driver is expected to operate the vehicle for an extended period of time to reduce the water and/or anti-freeze in the oil pan.
The inventors herein have recognized several disadvantages with the above approach. For example, the above system relies on actions initiated by the driver to address oil contamination. However, the operator may be unwilling, or unable, to provide the requested operation. For example, the operator may be unwilling to consume additional fuel to provide the requested operation. As another example, the operator may have other scheduled activities to carry out, or the operator may be stuck in traffic. Finally, in hydrogen-fuelled engines, because of the large volume of water by-products produced, simply extending driving operation of the vehicle may exacerbate the water contamination of the oil rather than reduce it.
As such, in one approach, a system for an internal combustion engine including an engine block having a cylinder, an oil delivery system coupled to the engine block including an oil reservoir at least partially enclosing an oil emulsion, the oil delivery system providing lubricating oil to at least one cylinder in the engine, a heat adjustment mechanism coupled to the engine, and a controller configured to adjust the heat delivered to the engine, via the heat adjustment mechanism, in response to an indication of water in the oil emulsion. For example, water concentration in the emulsion may provide such an indication. However, other indications, such as emulsion viscosity, may also be used.
In this way, by increasing the temperature of the engine, and thus the oil, it may be possible to evaporate the condensed water in the oil and thereby remove water from the oil, decreasing oil degradation. Additionally, or alternatively, it may be possible to reduce ice formation that may block an oil pick-up tube. Likewise, it may be possible to reduce oil viscosity to maintain system operation. In one example, the oil temperature may be increased via a block heater, such as used for improving cold starting in cold climates. In another example, the oil temperature may be increased by adjusting the engine cooling system. In still another example, the oil temperature may be increased by an oil heater in the oil pan. Still other examples are also possible as described herein.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.